I use these little razors strictly for exfoliating, so I can't really remark on how they perform for eyebrow maintenance. My skin is so dry this is the best way to REALLY exfoliate my face. I've used lots of brands, usually just whatever I come across while at the store. These are some of the better ones I've tried.
-first of all, this can be a bit tricky and I have made some embarring cuts on my face with some of the razors I've used. But I didn't have that issue with these. They are sharp but I'm not scared to use them on my face. Just like with any razor, they aren't meant to last a really long time. I'm guessing because I use them on my entire face and not just around my brows, I can get a couple of really good uses out of each one before needing a new one. But they are inexpensive and you get 12 so it's not a big deal.
Also, the covers actually stay on the razors, (which is an issue I've had with other brands), and the colors are cute!